  $(document).ready(function($) {
  	 var svg_ticks_tspan=$('tspan');
     var svg_ticks_text=$('text');
     
     // fetch the start and end ticks
  	 var target_idx=[];
  	 for(var i=0;i<svg_ticks_tspan.length;i++){
         if(svg_ticks_tspan[i].textContent==="0" || svg_ticks_tspan[i].textContent==="8") {
         	 target_idx.push(i);
         }
  	 }
     console.log(svg_ticks_text);
     //calculate the location of title
     var x=(eval(svg_ticks_text[target_idx[0]].getAttribute('x'))+eval(svg_ticks_text[target_idx[1]].getAttribute('x')))/2;
     var y=(eval(svg_ticks_text[target_idx[0]].getAttribute('y'))+eval(svg_ticks_text[target_idx[1]].getAttribute('y')))/2;


     // var title_span;

  });


